# Chiral transfer of angular momentum

## TL;DR

This paper demonstrates that chiral, time-periodic motion of an inner sphere in a viscous fluid can transfer angular momentum to an outer fixed sphere, revealing a novel mechanism for angular momentum transfer.

## Contribution

It introduces the concept that chiral motion in viscous fluids can induce torque transfer, a new insight into fluid dynamics and angular momentum transfer mechanisms.

## Key findings

- Chiral motion can generate non-zero torque on a fixed sphere.
- Angular momentum transfer occurs through viscous fluid interactions.
- Chirality is essential for the transfer mechanism.

## Abstract

Suppose that viscous fluid is contained in the space between a fixed sphere $S_2$ and an interior sphere $S_1$ which moves with time-periodic velocity ${\bf U}(t)$ and angular velocity ${\bf \Omega}(t)$, with $ \left<{\bf U}(t)\right> = \left<{\bf \Omega}(t)\right> = 0$. It is shown that, provided this motion is chiral in character, it can drive a flow that exerts a non-zero torque on $S_2$. Thus angular momentum can be transferred through this mechanism.